int memcmp( const void *s1, const void *s2, size_t n )

	- prototype in string.h, mem.h

	- compares two strings s1 & s2 for a length of n bytes,
	  returning a value:

			< 0   if s1 < s2
			= 0   if s1 = s2
			> 0   if s1 > s2